The present invention relates, in general, to buildings, and, more particularly, to building roof structures.
Metal building roof systems often use screws to fasten the elements of such roof systems to a purlin deck. Such systems require penetration of the roof cladding. If a screw becomes loosened during the life of the roof, a leak path is formed through which water can flow, thereby penetrating the roof and flowing into the building.
One alternative to requiring penetration is to construct a roof system wherein clips are used to fasten roof cladding to the purlin deck. In such systems, only the end laps have penetration. However, at such end laps, the screws penetrating the cladding produce leak paths.
A further problem with such roof systems involves large span buildings. Thermally induced expansion and contraction in such large span buildings causes movement of the end lap, thereby enlarging any screw holes. Such enlarged screw holes become potential leak paths through which water can penetrate into the building.
Expansion clips located at the end laps have not been successful for a variety of reasons.